Assessing the dynamics of soil microbial biomass carbon and labile carbon pools across different forest types of Mizoram, India

This study investigated soil organic carbon (SOC) pools and soil microbial biomass carbon (SMBC) across three forest types in Mizoram, India: Secondary Moist Bamboo Brakes, East Himalayan Moist Mixed Deciduous Forest, and Cachar Tropical Semi-Evergreen Forest. SOC is crucial for global biogeochemical cycles, influencing nutrient availability and ecosystem resilience. The study highlights the impact of forest type on SOC dynamics and microbial activity. The Secondary Moist Bamboo Brakes exhibited an Active Pool (VLC + LC) of 1.21% and a Passive Pool (LLC + NLC) of 0.78%, with SOC of 1.58% and SMBC of 340.72 mg/kg, indicating a balanced microbial presence. The East Himalayan Moist Mixed Deciduous Forest had relatively higher SOC (2.49%) and SMBC (352.31 mg/kg), suggesting increased microbial activity and faster carbon turnover. The Cachar Tropical Semi-Evergreen Forest recorded the highest SOC (2.51%) and significant SMBC (348.73 mg/kg), with the highest Very Labile Carbon (VLC) at 1.06%. Dehydrogenase activity (DHA), a key indicator of microbial metabolic activity, was highest in the East Himalayan Moist Mixed Deciduous Forest (6.42 µg TPF/g/h) and lowest in the Secondary Moist Bamboo Brakes (5.62 µg TPF/g/h). Correlations between SMBC and SOC pools were weak, with VLC and LC showing significant positive relationships with TOC (r = 0.636 and 0.693). These findings underscore the importance of forest type in shaping SOC and microbial dynamics, with implications for sustainable land management and carbon sequestration strategies in tropical forests.